According to my copy of the Standard Catalog of Smith & Wesson, which is probably the book Jay is referring to,
That revolver should be a 7 shot, and "Patent dates on the cylinder of 'April 3, 1855 & July 5, 1859' have been observed".
The price ranges are Poor 100, fair 200, good 250, VG 350, fine 500, exc 800, and exc + 2250.
(of course these are only a guide).
In 2005 a model 1, 2nd issue in "excellent" condition listed for $3,500 in the Old Town Station Dispatch.
It said under the "price check" section of this model info.
Hope this helps.